scsi: ufs: ufs-mediatek: Support multiple VCC sources

Support multiple VCC sources in MediaTek UFS platforms.

Two options are provided and distinguished by specific device tree
attributes as below examples,

[Option 1: By numbering]
mediatek,ufs-vcc-by-num;
vcc-opt1-supply = <&mt6373_vbuck4_ufs>;
vcc-opt2-supply = <&mt6363_vemc>;

[Option 2: By UFS version]
mediatek,ufs-vcc-by-ver;
vcc-ufs3-supply = <&mt6373_vbuck4_ufs>;

Link: https://lore.kernel.org/r/20220616053725.5681-11-stanley.chu@mediatek.comSigned-off-by: Alice Chao <alice.chao@mediatek.com>
Signed-off-by: Peter Wang <peter.wang@mediatek.com>
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/ufs/host/ufs-mediatek.c

@@ -669,6 +669,49 @@ static u32 ufs_mtk_get_ufs_hci_version(struct ufs_hba *hba)
 	return hba->ufs_version;
 }
 
+#define MAX_VCC_NAME 30
+static int ufs_mtk_vreg_fix_vcc(struct ufs_hba *hba)
+{
+	struct ufs_vreg_info *info = &hba->vreg_info;
+	struct device_node *np = hba->dev->of_node;
+	struct device *dev = hba->dev;
+	char vcc_name[MAX_VCC_NAME];
+	struct arm_smccc_res res;
+	int err, ver;
+
+	if (hba->vreg_info.vcc)
+		return 0;
+
+	if (of_property_read_bool(np, "mediatek,ufs-vcc-by-num")) {
+		ufs_mtk_get_vcc_num(res);
+		if (res.a1 > UFS_VCC_NONE && res.a1 < UFS_VCC_MAX)
+			snprintf(vcc_name, MAX_VCC_NAME, "vcc-opt%u", res.a1);
+		else
+			return -ENODEV;
+	} else if (of_property_read_bool(np, "mediatek,ufs-vcc-by-ver")) {
+		ver = (hba->dev_info.wspecversion & 0xF00) >> 8;
+		snprintf(vcc_name, MAX_VCC_NAME, "vcc-ufs%u", ver);
+	} else {
+		return 0;
+	}
+
+	err = ufshcd_populate_vreg(dev, vcc_name, &info->vcc);
+	if (err)
+		return err;
+
+	err = ufshcd_get_vreg(dev, info->vcc);
+	if (err)
+		return err;
+
+	err = regulator_enable(info->vcc->reg);
+	if (!err) {
+		info->vcc->enabled = true;
+		dev_info(dev, "%s: %s enabled\n", __func__, vcc_name);
+	}
+
+	return err;
+}
+
 /**
  * ufs_mtk_init - find other essential mmio bases
  * @hba: host controller instance
@@ -1179,7 +1222,6 @@ static int ufs_mtk_apply_dev_quirks(struct ufs_hba *hba)
 	else
 		ufs_mtk_setup_ref_clk_wait_us(hba,
 					      REFCLK_DEFAULT_WAIT_US);
-
 	return 0;
 }
 
@@ -1197,6 +1239,8 @@ static void ufs_mtk_fixup_dev_quirks(struct ufs_hba *hba)
 		hba->dev_quirks &= ~(UFS_DEVICE_QUIRK_DELAY_BEFORE_LPM |
 			UFS_DEVICE_QUIRK_DELAY_AFTER_LPM);
 	}
+
+	ufs_mtk_vreg_fix_vcc(hba);
 }
 
 static void ufs_mtk_event_notify(struct ufs_hba *hba,

drivers/ufs/host/ufs-mediatek.h

@@ -83,6 +83,7 @@ enum {
 #define UFS_MTK_SIP_DEVICE_RESET          BIT(1)
 #define UFS_MTK_SIP_CRYPTO_CTRL           BIT(2)
 #define UFS_MTK_SIP_REF_CLK_NOTIFICATION  BIT(3)
+#define UFS_MTK_SIP_GET_VCC_NUM           BIT(6)
 #define UFS_MTK_SIP_DEVICE_PWR_CTRL       BIT(7)
 
 /*
@@ -144,6 +145,16 @@ struct ufs_mtk_host {
 	u32 ip_ver;
 };
 
+/*
+ * Multi-VCC by Numbering
+ */
+enum ufs_mtk_vcc_num {
+	UFS_VCC_NONE = 0,
+	UFS_VCC_1,
+	UFS_VCC_2,
+	UFS_VCC_MAX
+};
+
 /*
  * SMC call wrapper function
  */
@@ -183,6 +194,9 @@ static void _ufs_mtk_smc(struct ufs_mtk_smc_arg s)
 #define ufs_mtk_device_reset_ctrl(high, res) \
 	ufs_mtk_smc(UFS_MTK_SIP_DEVICE_RESET, &(res), high)
 
+#define ufs_mtk_get_vcc_num(res) \
+	ufs_mtk_smc(UFS_MTK_SIP_GET_VCC_NUM, &(res))
+
 #define ufs_mtk_device_pwr_ctrl(on, ufs_ver, res) \
 	ufs_mtk_smc(UFS_MTK_SIP_DEVICE_PWR_CTRL, &(res), on, ufs_ver)